A George Mason University administrator, wanted on felony charges that he videotaped sex acts with underage partners and tried to extort money from at least one of his victims, was arrested late Tuesday night by D.C. police, who found him semiconscious in a city motel.

Ronald J. Sinacore, 55, was arrested at 11:45 p.m. at the Days Inn in the 2700 block of New York Avenue NE after police received a tip from Fairfax County investigators. He was hospitalized after an apparent suicide attempt.

Police said Sinacore appeared to be sick as a result of "ingesting" something and was taken to Howard University Hospital. Sinacore's attorney, Calvin Steinmetz, confirmed that his client had "tried to take his own life."

Prosecutors said Sinacore will be extradited to Fairfax County to stand trial when he is released from the hospital.

Sinacore, an associate director in George Mason's Office of Equity and Diversity Services, was charged last week on two felony counts for allegedly making and possessing child pornography. He was released from jail Monday on $20,000 bond over the objections of prosecutors.

Police returned Tuesday to his home in the 5400 block of Long Boat Court in Fairfax to serve three additional felony warrants but could not find him.

Instead, they found several notes suggesting that Sinacore might try to kill himself.

The latest charges against Sinacore include additional counts of possession and manufacturing of child pornography. He also is being charged with extortion for an alleged attempt to get $10,000 from a victim who told police that Sinacore threatened to release a video of him "having gay sex" if he did not pay.

Sinacore was placed on administrative leave at George Mason, his $83,000 annual salary suspended until the outcome of the investigation, a spokesman said yesterday. Staff writer Del Quentin Wilber contributed to this report.